When you use the new versions of Eclipse you will find that, Editors are disordered. That issue get serious, if you have more editors opened. The reason is recently Eclipse changed the editor sorting algorithm. and what we expect it "Most recently Used"=="mru".
let's see the solution:
eclipse direction /plugins/org.eclipse.platform_4.3.1.v20130911-1000/css/
find out the css file you are using，if you are mac it is e4_default_mac.css, open this file and change below false to true:
you can change to other css (other themes) by :Preferences->General->Appearance
Another way to change this style is by "Eclipse Css Editor", which is a plug-in. you can download it from "http://download.eclipse.org/e4/updates/0.12" then open "Preferences->General->Appearence":